WASHINGTON — Russia is advancing the unmanned launch of a Soyuz spacecraft to the International Space Station after post-undock inspection of a Progress cargo spacecraft showed no damage from a coolant leak.
Roscosmos announced on Feb. 18 that RSC Energia’s Council of Designers has recommended that the Soyuz-2.1a launch of the Soyuz MS-23 spacecraft take place at 7:32 p.m. EST on Feb. 23 from the station two days later , just before the arrival of the SpaceX Crew-6 mission, currently scheduled for early February 26th.
Soyuz MS-23 launches uncrewed because of a coolant leak in the Soyuz MS-22 spacecraft in December, which led Roscosmos to conclude the spacecraft was unable to safely return its crew of three. Soyuz MS-23 will replace Soyuz MS-22, and this damaged spacecraft will return to Earth unmanned.
The launch decision, Roscosmos said, was made after an inspection of the Soyuz MS-23’s cooler while the launch at the Baikonur Cosmodrome was being prepared. These inspections revealed no damage to it.
The announcement came after the Progress MS-21 cargo vehicle undocked from the station in late February. That spacecraft also suffered a coolant leak on Feb. 11, prompting Roscosmos to delay the Soyuz MS-23 launch from Feb. 19 to investigate the issue. Roscosmos initially said the Soyuz MS-23 launch could be pushed back to early March, but didn’t explain why it was pushed back to February in its most recent announcement.
After undocking, the station’s cosmonauts sent commands to rotate the Progress spacecraft 180 degrees “so we can get additional visual inspections and documentation of where the coolant leak occurred,” said Jeff Arend, manager of the ISS systems engineering and integration offices of NASA. during a February 17 briefing on the upcoming mission of the Boeing CST-100 Starliner crew to the station.
However, high-definition video transmissions during undocking showed no obvious signs of damage like that seen with Soyuz MS-22. While Roscosmos planned to leave Progress just one orbit after undocking, it delayed those plans while it studied the data it received.
Roscosmos announced early February 18 that it would proceed with the deorbiting of Progress, with reentry scheduled for 10:57 p.m. Eastern Time via the South Pacific. It previously stated that inspections had revealed no damage to the spacecraft and had even considered docking Progress back with the station for additional studies.
Arend noted that the Progress had been scheduled to undock since late December and was unaffected by the coolant leak. This coolant system controls temperatures for the spacecraft’s avionics, and he said that even without it, the spacecraft should be able to operate normally for its deorbiting.
“Our Russian colleagues have evaluated how long they can run this vehicle without cooling and we’re well within limits,” he said. “We believe that all avionics will work as planned and there has been no impact on the propulsion system.”